We need to rent a car for a week at the Zurich airport. We will have our 8 month old with us. Does anyone have any experience with renting a car, with a child seat, from either Enterprise or Sixt? Were the child seats in working order? Did the child seats seem clean?

Yes, the rental car seats are fine and in good condition, clean what is very important. Much better than in the USA and I have experience in renting car with car seats in different countries.
We usually go for Sixt, I can't say anything about Enterprise.

But renting a car seat is quite expensive (around 30 CHF/a day with a weekend rent) so maybe it makes more sense to bring your own? Just an idea, I am aware how much hustle involved in carrying the car seat around but an airline will check it in for free.

I anticipate you will not be disappointed in the quality of your little Prince/Princess's rented Throne.

Regards

Ian

Rented a car ( golf wagon ) two weeks ago at zurich airport for 4days to travel to Locarno from Enterprise and could not be happier. The golf wagon was brand new with about 300 km and of course clean .

Rented a car ( golf wagon ) two weeks ago at zurich airport for 4days to travel to Locarno from Enterprise and could not be happier. The golf wagon was brand new with about 300 km and of course clean .

Yes! Thank you! I was wondering if there was a way to verify specific car seats but now I am understanding that if they do not have this specification already on them, then the car seat does not qualify.

if they do not have this specification already on them, then the car seat does not qualify.

You can ask the manufacturer of the car seat. Most manufacturers sell the same seats in various countries. Even if the seat is approved, the manufacturer may only put the label for the country in which the seat is being sold.